Antitail spin device



May 10, 1932. TETLOW 1,858,195

ANTITAIL SPIN DEVICE Filed May 2, 1950 Patented May 10, 1932 UNlTEfiSTATES LEWIS J. TETLOW, OF HOLYOKE, MASSACHUSETTS ANT'ITAIL SPIN DEVICEApplication filed May 2, 1930. Serial No. 449,275.

' to normal flying position.

An object of the present invention is the provision of means which maybe readily secured to the elevators of an airplane and simultaneouslycontrolled from the operators rcockpit by a single lever to create anupward pressure upon the bottom face of the stabilizer when theelevators are swung downwardly.

Another object of the present invention is the provision of one or moreof these tail lifters to each elevator in order to obtain the maximumpressure possible against the bottom face of the stabilizer to assist inimmediately raising the tail end of the plane when the pilot observes onthe instrument board the initial slipping of the plane.

The greatest hazard in aviation at the present time is what is known asthe tail spin and it is practically impossible to right a machine onceit goes into a tail spin. Itis with this thought in mind that thepresent invention has been designed in order to lessen the chance of aplane going into a tailspin, and which will enable a pilot to readilyright the plane to its normal flying position upon the instrumentshowing that the plane is beginning to slide. Upon observing thisindication on the instrument board, the pilot can immediately throw hiscontrol lever to drop the elevators so as to create air pressure zonesupon the bottom face of the stabilizer due to the air pressure createdby the force of air emitting thru the tail lifters in a conceutratedarea which force is sufficient to check the slipping and immediatelyraise the tail end of the plane to its normal flying position.

In the drawings:

Figure 1 is a. top plan view of an airplane fuselage having pipes on theoutside with the controls passing thru for controlling the tail liftersof the present invention.

Figure 2 is a side elevation of an elevator showing the tail liftingmeans secured thereto.

Figure 3 is a transverse section thru one of the tail lifters. I t

Figure 4 is a plan view of the elevators showing one or more of the taillifters applied thereto.

Figure 5 is a side elevation of one of the tail lifters showing thebeveled edges.

Figure 6 is a transverse section of an'elevator showing a modified formof tail lifter.

Referring more in detail to the drawings '10 indicates the fuselage ofan airplane having the usual cockpit 11 and control lever 12-, and alsoincluding the stabilizer 13, rudder L4, and elevators 15. Suitable tubes.16 are provided on the fuselage to receive the control wires 17 and 18from the rudder 1 1 and elevators 15 thru which the control wires passto the control lever 12.

The feature of the present invention resides in providing upon theelevators 15 suitable tail lifters 19. These tail lifters 19 may be ofany desired shape and accomplish the same result but for the purpose ofillustration, I have shown in the drawings a cylindrical tail lifter.derstood that I do not limit myself to-such a construction. Thecylindrical tail lifter shell 19 shown is provided with a centrallongitudinal slot 20 dividing the same into two substantially equalsemi-circular portions 21 and 22. The top portion 21 is of less lengththan the bottom portion 22 and has its forward edge beveled asat 23 soas to offer as little resistance as possible when the elevators areswung downwardlyto right the plane to its normal flying position. Thebottom portion 23 extends forwardly of the upper portion and is beveledofi as at 24. so as to form an air pressure zone with the'bottom face ofthe stabilizer 13 when the elevators are swung downwardly. These taillifters are detachably secured to the elevators by slipping the endportion of the elevators thru the slot 20 with the inclined edges 23 and24 facing in close proximity to the hinged However, it is to beunportion of the elevators adjacent the stabilizer whereby when thestabilizer is tilted downward the lower half of the tube 19 issubstantially closed. Suitable threaded openings are provided in thetail lifters to receive the screw 25 which passes thru openings in theelevators 15.

In some instances it may be desirable to attach more than one of thesetail lifters to each elevator as shown in Figure 4. This is to take careof the larger planes and give great er raising power to take care of theincreased weight of the larger planes. However, the construction of thetail lifters is identical and the result accomplished is the same. Itmay also be desirable to eliminate the upper portion 21 and if such isthe case the tail lifter may be constructed as shown in Figure 6. Thislifter is applied to the bottom face of the elevators and may be of anydesired shape or contour and is provided with flanges 26 for securingthe same to the elevators and also includes the beveled edge 24 forresting closely the bottom face of the stabilizer so as to form an airpressure zone to create an upward pressure on the stabilizer for rais ngthe tail end of the plane to its normal flying position.

W'ith a plane equipped with the tail 1] fters of the present inventionthe danger of tail spinning is greatly reduced. Should a pilot :beflying along under normal conditions and then something happen thatwould cause the planeto begin sliding it would be noticed immediately.on the instrument board. The pilot would then move his control lever 12so as to throw the elevators 15 downwardly and due to the fact that theelevators are provided with one or more of the tail lifters, as the casemay be, air is passed thru the lifters 19 and concentrated against thebottom face of stabilizer 13 due to the forward edge 24 of the lowerportion 22 of the lifters terminating in close proximity to the bottomface of the stabilizer to substantially close the lower half of the tube19 and forming an air pressure zone which assists in raising the tailend of the. plane to its normal flying position. Thus it will be seenthat the possibility of tail spinning is greatly reduced when a plane isequipped with the tail lifters of the present invention.

What I claim is: r

1. In an airplane having fuselage, a stabilizer, a rudder, andelevators; air current actuated tail lifting means attached to saidelevators.

2. The device of claim 1 in which the tail lifting means defines apassageway to create an upward pressure upon the bottom face of thestabilizer'when the elevators are moved downwardly.

3. The device of claim 1 which the tail lifting means comprises a hollowmember on each elevator the axes of said members being parallel to theplane of the elevator.

4. The device of claim 1 in which the tail lifting means comprises ahollow member on each elevator having a beveled end adapted to form anair pressure zone with the bottom face of the stabilizer.

5. The device of claim 1 in which the tail lifting means forms an airduct both above and below the elevator.

6. The device of claim 1 in which the tail lifting means is a tubularmember bisected longitudinally by the elevator.

7. The device of claim lin whiohaplurality of tail lifting means isattached to each elevator.

8. The device of claim 1 in which the tail lifting means froms an airduct on the bottom face of the elevator.

9. The device of claim 1 in which the tail lifting means is a slottedtubular member having a beveled end.

10. The device of claim 1 in which the tail lifting means comprises atubular member equally spaced above and below the elevator and havingthe lower portion extending forwardly of the upper portion.

11. An airplane comprising a fuselage, a

stabilizer, a rudder, control mechanism, elevators and air currentactuated tail lifting means detachably secured to said elevators at eachside of the fuselage.

12. In an airplane having a stabilizer at the rear of the fuselage andhaving separate elevators hingedly connected to the stabilizer, a deviceto deflect the rear or tail of the plane as a tail spin is about to beinitiated, said device consisting of an elongated shell longitudinallypositioned on the bottom surface of each elevator forming with saidsurface an air passage terminating in proximity to the hinged end,whereby as the plane tends to move rearwardly, a downward movement ofboth elevators will cause the air passing thru the shells to be directedagainst the bottom surface of the stabilizer to resist the tendency ofthe tail of the plane to sink by gravity in order to give the pilot timeto right the plane.

a In testimony whereof I aflix my signature. LEWIS J. TETLOWV.

